Articles | Volume 22, issue 2
https://doi.org/10.5194/cp-22-265-2026
© Author(s) 2026. This work is distributed under the Creative Commons Attribution 4.0 License.
10 000 years of snow avalanche activity in western Norway: a multiproxy lake sediment record from Lake Vatnasetvatnet, Hardanger
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- Final revised paper (published on 06 Feb 2026)
- Preprint (discussion started on 30 Jul 2025)
Interactive discussion
Status: closed
Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor
| : Report abuse
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RC1: 'Comment on egusphere-2025-2910', Anonymous Referee #1, 05 Sep 2025
- AC2: 'Reply on RC1', Johannes Hardeng, 22 Oct 2025
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RC2: 'Comment on egusphere-2025-2910', Anonymous Referee #2, 06 Sep 2025
- AC3: 'Reply on RC2', Johannes Hardeng, 22 Oct 2025
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EC1: 'Comment on egusphere-2025-2910', Gerilyn (Lynn) Soreghan, 07 Sep 2025
- AC1: 'Reply on EC1', Johannes Hardeng, 22 Oct 2025
Peer review completion
AR – Author's response | RR – Referee report | ED – Editor decision | EF – Editorial file upload
ED: Publish subject to minor revisions (review by editor) (01 Nov 2025) by Gerilyn (Lynn) Soreghan
AR by Johannes Hardeng on behalf of the Authors (19 Dec 2025)
Author's response
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ED: Publish subject to minor revisions (review by editor) (21 Dec 2025) by Gerilyn (Lynn) Soreghan
AR by Johannes Hardeng on behalf of the Authors (22 Dec 2025)
Author's response
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ED: Publish as is (23 Dec 2025) by Gerilyn (Lynn) Soreghan
AR by Johannes Hardeng on behalf of the Authors (31 Dec 2025)
Author's response
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This well written and interesting paper investigates the sedimentary record of a high-mountain lake in Western Norway. The author focus on the event-layer chronology and put this in the context of avalanche frequency as a result of climate and weather patterns. They identify three intriguing periods in the Holocene when avalanche activity was highly different. These findings are coinciding with patterns of flood and glacial activity. Moreover, there seems to be a clear link to NAO on a centennial time scale, with all of these players influencing the moisture distribution, temperature (snowline!) and atmospheric circulation patterns. The topic is highly relevant for the Journal Climate of the Past and I was pleased to read this well-structured and well written contribution.
I do have some key comments upfront, followed by some detailed comments.
I welcome the applied dual method of identifying event layers (CT thresholding, RoC) minimizing subjectivity. However, my main concern is that the authors interpret all event layers solely as avalanche-induced ("wet snow avalanches entering an ice-free lake"), and do not consider them being deposited by extreme floods caused by precipitation events. There is no doubt that this basin is influenced by avalanches, which leave some traces in the sedimentary record. However, I am missing a discussion on extreme precipitation events, and how the respective layer can be distinguished. The authors mention that "only small, intermittent streams and no evidence of substantial fluvial reworking" occur and "Given their limited drainage area, the contribution of these streams to the influx of allochthonous minerogenic sediments into the lake is minimal". But there are plenty of high-mountain lake-sediment records that are clearly punctuated by flood deposits, in particular also in basins with no permanent inflow. These lakes also lack major deltas or alluvial fans, as is the case of the Lake Vatnasetvatnet, but this does not mean that extreme precipitation events do not deliver minerogenic deposits to the basin. In fact, the paper does not describe in detail the sedimentologic characteristics of the event layers. Fig. 5 is very nice, and displays for one case the detailed sediment structures, which is, however, in my view highly similar to many well-described flood turbidites from comparable lakes. There is the sharp base, a basal sand, a graded unit, disperse organic matter and a fining-upward cap (why is "inverse graded" on Fig. 5 and "fining upward" in the text?). Some high-density inversions with thin layers towards the base of the event deposit (beautifully shown on the CT data) may also indicate the waxing and waning of the flood (well described in literature), a process that I cannot imagine well in an avalanche. So I am very reluctant to assign all these layers to avalanches. As this is the key interpretation of this study, I expect at least a detailed discussion and explanation, showing more sedimentologic features of the layers, why they cannot be deposited by floods. There must be avalanche-specific features of event layers in the literature, but what I see seems highly reminiscent of flood layers. Several types of avalanches are mentioned (ice-free lake, on frozen lake, wet snow, rain-induced), is it also possible that they can be discerned? In the end, all layers are solely considered to be wet avalanches in an unfrozen lake and I am not convinced that this is the case. This uncertainty is also caused by the lack of an instrumental or historic calibration, i.e. a ground truthing that identifies a recent prominent layer and correlates it to a known event. Not sure such time series exist for Lake Vatnasetvatnet, but it should be attempted or at least commented why this is not possible.
What is also is intriguing in this context, is that the avalanche record does match closely the flood records of other Norwegian lakes (Fig. 9). In all three distinguished Holocene periods, the authors mentions matching records of snowmelt floods chronologies, so the pattern is the same. This leaves me uncertain whether avalanches really match flood records, or whether we indeed look rather at an avalanche or a combined record.
As last general comment, I would say that I rather recognize four Holocene periods with characteristic event layer patterns: The 6500 to 4200 cal BP window is summarized in one epoch, but I do recognize a period 5500-4200 as an interval with intriguing lack of event layers, and 6500-5500 as an interval with very high activity (Fig. 9).
Some Detailed/technical comments
55: The authors provide as examples of sediment-based avalanche reconstructions four Norwegian and one Alpine case studies. Considering the discussion above on distinction between flood and avalanche deposits, a summary of key criteria and key sedimentary structures would be very helpful here.
173: Why is this discussion of the cirque (barely shown on Fig. 2) so important? This is not marked as avalanche track. It is interesting for the Late Glacial situation, ok, but if you mention it, the cirque should be shown fully on a slightly larger map.
Figure 5 is very well done, nice. I fully agree with the interpretation of the sharp lithologic transition coinciding with the disappearance of the glacier in the catchment, as supported by the age model. But I got a bit lost in the description of the stratigraphy. Four cores were retrieved, two were merged into one composite section (VABG) in the western basin (122, 109), this is fine. The shorter one was taken to obtain the sediment-water interface, but why was it not sampled at same location as the piston core? Then two cores were recovered from the eastern basin (209, 309), but only one is shown in Figure 5 (209) but 309 is discussed as well in the text. It is all a bit hard to follow.
330: "and represent instantaneous deposits, i.e., event layers". This statement is here a bit premature. You describe here the sediment, and start right away with an interpretation of depositional environment but one needs to develop the case why these are event deposits. A more detailed description of sedimentary features will help.
363: "For CT thresholding, we classified depths with more than 40% minerogenic sediment as event layers": So the 40 % are a strong quantitative criteria, but it is not clear how this value was obtained by the CT data.
364: "Layers >3 mm thick were marked as instantaneous deposits (slumps) in the rBacon age-depth model to improve chronological accuracy and better reflect true depositional ages (Fig. 8)". The term "slump" is not an appropriate term here, as it a remobilized slope deposits. This is maybe a fix term in the Bacon software, but it should not be used here, these are not slumps.
The GPR profile are not as clear as they are interpreted. It would be useful to make them larger: do we really see these 6 m of sediments? Maybe reflection seismic surveys would give better picture of the sediment architecture, but I guess the authors make the best out of their available site survey data. On Fig. 2a, the cores should be labelled as well. I wonder why were cores were not taken on GPR profiles? Consequently, the cores were obviously projected on the radar lines, this should mentioned.
1-sigma is rather confident for the age model, usually, such lacustrine age models are done with a 2-sigma confidence interval. This just as a remark, in this case, it would not change the interpretation a lot, I guess.
In summary, I like the paper but would like to see the key issue addressed, i.e. the distinction between flood and avalanche deposits. Overall, I look forward to see this published after moderate (I only can chose minor or major, so I made minor) revisions.